The present invention relates to an induction generator comprising an injection-molded housing of plastic material provided with a port and further comprising one or more pole shoe(s), an associated permanent magnet and a plastic bobbin inserted into the port and having wound thereon a coil which is connected through soldering eyelets, to two contact tags in communication with an externally guided cable. It further comprises a mounting element, with the port, at the end facing the soldering eyelets being closely sealed by means of a lid welded to the housing. It also relates to a method of producing this induction generator.
An induction generator of the afore-described type is taught by DE-OS No. 34 00 870. According to the induction generator described therein, an orifice of a port extending through the housing is closely sealed by means of a flange formed on a cup-shaped coil-carrying bobbin and welded to the housing, with the pole shoes along with the permanent magnet being located in a recess of the coil-carrying bobbin.
The disadvantages involved with heretofore conventional induction generators relate to corrosion problems occurring in the pole shoe region caused by the ends of the pole shoes protruding from the housing. Such problems can be avoided by the use of high-quality materials for the manufacturer of the pole shoes. However, the use of such high-quality materials inevitably incurs substantial costs.
As metal particles or chips are likely to adhere to the protruding pole shoes in form-locking manner, a short-circuiting risk and a change in the output signal of the induction generator, respectively, cannot be excluded. A further disadvantage is that the joints require close tolerances to the pole shoe dimensions for proper operation. In addition, leak proofness of conventional induction generators, particularly in the pole shoe region, is considered critical. This is attributable to a plurality of seams and joints involving an enhanced risk of damage caused by changing temperature and impact stresses. Equally disadvantageous, is the need to provide for different generator configurations, different bobbins along with pole shoes and the associated permanent magnet, causing an increase in the manufacturing costs of conventional induction generators.